The present invention relates to a valve and a valved trocar jacket tube used in endoscopic surgery in pneumoperitoneum.
FIG. 1 shows a conventional valved trocar jacket tube wherein the valved trocar jacket tube 1 is composed of a cylindrical jacket 2 and a casing 3 secured to the top of the jacket 2. The casing 3 has a circular opening 3a on the upper part thereof. Furthermore, the casing 3 contains a valve 4 for opening and closing the opening 3a and a spring 5 for urging the valve 4 towards the closing direction therein.
In the case when the valved trocar jacket tube 1 thus constituted is employed, as shown in FIG. 2, a physician inserts the jacket 2 of the valved trocar tube 1 in a site, for example, the incised portion of the abdomen Pa of a patient P being an object to be operated. In case of using a clamp or the like, an adapter 6 being called by the name of reducer or introducer composed of a leakage preventing valve 6A having an opening 6a the inside diameter of which corresponds to the outside diameter of the clamp or the like and an outer cylinder 6B is employed. The physician sets the clamp or the like having a diameter corresponding to the diameter of the opening 6a of the adapter 6 thereto, and the clamp or the like so arranged is inserted through the opening 3a of the casing 3. In this case, the valve 4 is opened against the spring force of the spring 5 due to insertion of the adapter 6. As a result, leakage of an inert gas injected into an abdominal cavity for conducting easily endoscopy and the like is prevented.
According to the conventional valved trocar jacket tube 1, however, there is such a problem that since the diameter of the opening 3a defined on the casing 3 is stationary, it is required to use an adapter 6 having the diameter corresponding to that of the clamp or the like 7 to be employed on all such occasions, and such substituting operation required incidentally is troublesome, so that the operator's manipulation is prevented.
Furthermore, there are such problems that since any contour in the opening 6a of an adapter 6 is circular, the contour of a clamp or the like 7 is limited to that having a circular shape and that since the standard sizes in the opening 6a of an adapter 6 are usually 5, 10, and 12 mm, a clamp or the like 7 having an intermediate size such as 6 mm or 8 mm cannot be used, so that sizes of the clamp or the like 7 are also restricted.
Besides, since the inside diameters in the openings 6a of adapters 6 and the outside diameters of clamps or the like are nominal values, respectively, there are such problems that the inside diameter of an adapter 6 does not match with the outside diameter of a clamp or the like 7 in reality, and as a result, either such clamp or the like 7 is impossible to use or there is a case of arising leakage.